1. Field of the Invention
The present invention relates to an electrical connector having a pair of connector housings which prevent looseness caused by vibration between the housings during operation of a motor vehicle to ensure electrical connection between male and female terminals in the connector housings.
2. Background Art
FIGS. 10 and 11 show a conventional electrical connector disclosed in Japanese Patent Application laid-open No. 2002-198127. The connector, which is designated by numeral 61, has a male connector 63 accomodating a receptacle terminal 62 and a female connector 65 accomodating a male terminal 70. The male connector 63 has a male connector housing 64 made of a synthetic resin, and the male connector housing 64 has an outer hood 64b with an inner surface where looseness preventing protrusions 67 are unitarily formed. Each looseness preventing protrusion 67 engages with an outer surface of a female connector housing 68 for the pin terminal 70 to prevent looseness of the connectors 63 and 65 in a lateral direction of the connector.
The male connector housing 64 has an inner housing 64a and the outer hood 64b having a rectangular cylinder section. The inner housing 64a receives the receptacle terminal 62. The receptacle terminal 62 is double locked by a front holder 69 made of a synthetic resin. The inner housing 64a has a base section receiving a packing 71. The looseness preventing protrusion 67 has a generally rectangular shape.
Between the hood 64b and the inner housing 64a, the female connector housing 68 is inserted. FIG. 11 shows a state just before engagement of the connectors 64 and 68. On mating of the connectors 64 and 68, the terminals 62 and 70 connect to each other. At the same time, a fore end of the female connector housing 68 contacts the packing 71, and a locking arm 72 of the hood 64b engages with a locking protrusion 74 of the female connector housing 68 so that the male connector 63 and female connector housing 68 are locked to each other. The protrusion 67 prevents looseness between the inner housing 64a of the male connector housing 64 and the front holder 69 in a lateral direction of the connector. This decreases wear of the terminals 62 and 70 which is due to vibration during operation of motor vehicles.
However, the connector 61 prevents looseness in the lateral direction of the connector but does not prevent looseness in a longitudinal direction of the connector. Thus, the terminals 62 and 70 scratch each other between them by vibration of the connector 61 during operation of the vehicle or its engine. This causes disadvantageously friction wear or friction corrosion.
Furthermore, the looseness preventing protrusion 67 is projected from an inner surface of the inner housing 64a so that the inner housing 64a contact the female connector housing 68 via the looseness preventing protrusion 67 to prevent looseness therebetween. But, the inner housing 64a receiving the terminal of the male connector housing 64 does not contact the female connector housing 68. Thus, the looseness of the inner housing 64a is not prevented so that the terminals 62 and 70 move toward each other longitudinally, possibly causing wear of the terminals 62 and 70.
In a long use of the connector, the looseness preventing protrusion 67 wears due to vibration during operation of the vehicle to provide a clearance between the hood 64b and an outer wall of the female connector housing 68. This may disadvantageously cause looseness even in a lateral direction of the connector.